/**
 * @作者 钟诚
 * @日期 2011-8-3
 * @时间 上午11:05:05
 * @描述
 * @版本
 */
package my.servlet;

import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.text.SimpleDateFormat;
import java.util.Arrays;
import java.util.Date;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.List;
import java.util.Random;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import net.sf.json.JSONObject;

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileItemFactory;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * @作者 钟诚
 * @日期 2011-8-3
 * @时间 上午11:05:05
 * @描述
 * @版本 v1.0
 */
public class UploadServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
	private static final Log log=LogFactory.getLog(UploadServlet.class);
	private String url;
	private String error;
	private String message;

	private String getError(String message) {
		JSONObject obj = new JSONObject();
		obj.put("error", 1);
		obj.put("message", message);
		log.debug(obj);
		return obj.toString();
	}

	public final String getUrl() {
		return url;
	}

	public final void setUrl(String url) {
		this.url = url;
	}

	public final String getError() {
		return error;
	}

	public final void setError(String error) {
		this.error = error;
	}

	public final String getMessage() {
		return message;
	}

	public final void setMessage(String message) {
		this.message = message;
	}

	@Override
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		response.setContentType("text/html; charset=UTF-8");
		// 文件保存目录路径
		String savePath = this.getServletContext().getRealPath("/") + "attached/";
		// 文件保存目录URL
		String saveUrl = this.getServletContext().getContextPath() + "/attached/";
		// 定义允许上传的文件扩展名
		String[] fileTypes = new String[] { "gif", "jpg", "jpeg", "png", "bmp" };
		// 最大文件大小
		long maxSize = 200*1024*1024;
		PrintWriter out = null;
		try {
			out = response.getWriter();
		} catch (IOException e1) {
			log.error(e1);
		}

		if (!ServletFileUpload.isMultipartContent(request)) {
			out.println(getError("请选择文件。"));
			return;
		}
		// 检查目录
		File uploadDir = new File(savePath);
		if (!uploadDir.isDirectory()) {
			out.println(getError("上传目录不存在。"));
			return;
		}
		// 检查目录写权限
		if (!uploadDir.canWrite()) {
			out.println(getError("上传目录没有写权限。"));
			return;
		}
		// 创建文件夹
		SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd");
		String ymd = sdf.format(new Date());
		savePath += ymd + "/";
		saveUrl += ymd + "/";
		File dirFile = new File(savePath);
		if (!dirFile.exists()) {
			dirFile.mkdirs();
		}

		FileItemFactory factory = new DiskFileItemFactory();
		ServletFileUpload upload = new ServletFileUpload(factory);
		upload.setHeaderEncoding("UTF-8");
		List items = null;
		try {
			items = upload.parseRequest(request);
			System.out.println(items.size());
		} catch (FileUploadException e1) {
			log.error(e1);
		}
		Iterator itr = items.iterator();
		while (itr.hasNext()) {
			FileItem item = (FileItem) itr.next();
			String fileName = item.getName();
			long fileSize = item.getSize();
			if (!item.isFormField()) {
				// 检查文件大小
				if (item.getSize() > maxSize) {
					out.println(getError("[ "
							+ fileName + " ]超过单个文件大小限制，文件大小[ "
							+ fileSize + " ]，限制为[ "
							+ maxSize + " ] "));
					return;
				}
				// 检查扩展名
				String fileExt = fileName.substring(fileName.lastIndexOf(".") + 1).toLowerCase();
				if (!Arrays.<String> asList(fileTypes).contains(fileExt)) {
					out.println(getError("上传文件扩展名["+fileExt+"]是不允许的扩展名。"));
					return;
				}

				SimpleDateFormat df = new SimpleDateFormat("yyyyMMddHHmmss");
				String newFileName = df.format(new Date()) + "_" + new Random().nextInt(1000) + "." + fileExt;
				try {
					File uploadedFile = new File(savePath, newFileName);
					item.write(uploadedFile);
				} catch (Exception e) {
					out.println(getError("上传文件失败。"));
					return;
				}

				JSONObject obj = new JSONObject();
				obj.put("error", 0);
				obj.put("url", saveUrl + newFileName);
				log.debug(obj);
				out.println(obj.toString());
			}
		}
	}

	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		doPost(req, resp);
	}
}
